The invention relates to an assembly with a mechanically inaccessible or difficult-to-access circuit, which has an electrical component that can be irreversibly changed by a current pulse; the irreversible change of the component is capable of switching the circuit from a first operating state into a second operating state. The invention also relates to a method for switching the operating state of an assembly.
In a multitude of applications, assemblies are only finally configured for their intended purpose upon initial operation or installation. The use of adaptable circuits permits the manufacturer to avoid having to produce and store a multitude of hard-wired assembly variants and instead to stock a supply of a single type of configurable assembly.
It is for example customary to adapt parts of a communications system to special requirements during installation. The adaptation is often carried out by means of so-called jumpers, i.e. pluggable bridging contacts, encoding switches, or other mechanical components. Another known method is the use of differently programmed memory chips.
European Patent Disclosure EP 0 652 567 A2 has disclosed a device and a method for adapting analog integrated circuits on a chip, which are encapsulated in a plastic housing. To this end, in addition to the actual circuit, the chip has an adaptation circuit with an interruptible electric element such as a fuse, a status detection unit for detecting the status of the electric element, a current source for generating a current for interrupting the electrical element, and a test state detection unit that also detects partially interrupted electrical elements. The actual circuit and the adaptation circuit are situated together on the same chip and are encapsulated together in the plastic housing.